Use ScopedTaskEnvironment instead of MessageLoopForUI in ui tests.

ui/events/gesture_detection/gesture_provider_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/gesture_detection/gesture_provider.h"
 
 #include <stddef.h>
 
 #include <memory>
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/gesture_detection/gesture_event_data.h"
 #include "ui/events/gesture_detection/motion_event.h"
 #include "ui/events/test/motion_event_test_utils.h"
 #include "ui/gfx/geometry/point_f.h"
 
 using base::TimeDelta;
@@ skipping 31 matching lines @@
 
 gfx::RectF BoundsForSingleMockTouchAtLocation(float x, float y) {
   float diameter = MockMotionEvent::TOUCH_MAJOR;
   return gfx::RectF(x - diameter / 2, y - diameter / 2, diameter, diameter);
 }
 
 }  // namespace
 
 class GestureProviderTest : public testing::Test, public GestureProviderClient {
  public:
-  GestureProviderTest() {}
+  GestureProviderTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI) {}
   ~GestureProviderTest() override {}
 
   static MockMotionEvent ObtainMotionEvent(base::TimeTicks event_time,
                                            MotionEvent::Action action,
                                            float x,
                                            float y) {
     return MockMotionEvent(action, event_time, x, y);
   }
 
   static MockMotionEvent ObtainMotionEvent(base::TimeTicks event_time,
@@ skipping 340 matching lines @@
 
   static void RunTasksAndWait(base::TimeDelta delay) {
     base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
         FROM_HERE, base::MessageLoop::QuitWhenIdleClosure(), delay);
     base::RunLoop().Run();
   }
 
   std::vector<GestureEventData> gestures_;
   std::unique_ptr<GestureProvider> gesture_provider_;
   std::unique_ptr<GestureEventData> active_scroll_begin_event_;
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 };
 
 // Verify that a DOWN followed shortly by an UP will trigger a single tap.
 TEST_F(GestureProviderTest, GestureTap) {
   base::TimeTicks event_time = base::TimeTicks::Now();
   int motion_event_id = 6;
   int motion_event_flags = EF_CONTROL_DOWN | EF_ALT_DOWN;
 
   gesture_provider_->SetDoubleTapSupportForPlatformEnabled(false);
 
@@ skipping 2386 matching lines @@
   event = ObtainMotionEvent(event_time, MotionEvent::ACTION_DOWN, kFakeCoordX,
                             kFakeCoordY + GetTouchSlop() / 2);
   EXPECT_TRUE(gesture_provider_->OnTouchEvent(event));
   event = ObtainMotionEvent(event_time, MotionEvent::ACTION_UP);
   EXPECT_TRUE(gesture_provider_->OnTouchEvent(event));
   EXPECT_EQ(ET_GESTURE_TAP, GetMostRecentGestureEventType());
   EXPECT_EQ(1, GetMostRecentGestureEvent().details.tap_count());
 }
 
 }  // namespace ui